Mesangial deposits of Lambda chain is seen in
**Core Concept**
Mesangial deposits of Lambda chain refer to the accumulation of lambda light chain proteins in the mesangium, a region of the glomerulus. This is a key feature of light chain deposition disease (LCDD), a complication of plasma cell dyscrasias such as multiple myeloma.
**Why the Correct Answer is Right**
The deposition of lambda light chains in the mesangium occurs due to the excessive production of monoclonal immunoglobulin light chains by malignant plasma cells. These light chains are too small to be effectively filtered by the glomerular basement membrane and instead accumulate in the mesangium, leading to mesangial expansion and potential glomerular dysfunction. The lambda light chain is more commonly associated with this condition due to its smaller size and higher proportion in the monoclonal immunoglobulin.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because kappa light chain deposits are more commonly associated with kappa light chain deposition disease, a different condition.
**Option B:** Incorrect because IgM deposits are characteristic of IgM nephropathy, a different glomerular disease.
**Option C:** Incorrect because IgA deposits are characteristic of IgA nephropathy, a different glomerular disease.
**Clinical Pearl / High-Yield Fact**
In patients with plasma cell dyscrasias, the presence of mesangial deposits of lambda light chains can be a clue to the diagnosis of light chain deposition disease. This condition can lead to progressive glomerular damage and renal failure if left untreated.
**Correct Answer: D. Lambda chain**